Should isoniazid prophylaxis be prescribed to the patients under tumor necrosis factor-alpha antagonists independent of tuberculin skin test?

The aim of this study was to present the follow-up results of 110 patients who were given anti-tumor necrosis factor alpha (TNF-α) therapy for rheumatic and dermatologic diseases in a country with a high rates of active and latent tuberculosis bacillus infection. Between February 2008 and January 2015, 110 cases in the age range of 23-77 who are using anti-TNF-α were included in the study retro-prospectively. 52.7% of them (n = 58) were male. The most common diagnoses were rheumatoid arthritis (42.7%) and ankylosing spondylitis (38.2%). Most frequently given treatment were infliximab 37.3% and etanercept 30.9%, respectively. The 65 patients whose first tuberculin skin test (TST) value "5 mm and above" was started daily 300 mg INH prophylaxis for 9 months but 3 patients had not been started because of refusing treatment. In only one case chemoprophylaxis has had to be interrupted because of high liver function test due to the INH prophylaxis. TST conversion was observed in 14 patients. Further follow-up, it was observed that 4 patients had TST's positivity. Isoniazide (INH) prophylaxis was started these 18 patients (42.9%). Although INH prophylaxis has been given in two patients, they developed active tuberculosis in follow-up. Considering the INH resistance in our country, all patients especially the ones with residual lesion and history of previous exposure, should be followed up closely during the anti-TNF-α treatment.